JP2860664B2 - Power supply control device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply control device that supplies power from another device that supplies power to a load.

[Prior Art] FIG. 6 is a circuit diagram showing an example of an apparatus for supplying power from a main apparatus 1 to an option apparatus 2 for use.

The optional device 2 is connected to the main device 1 via connectors CN1 to CN4.
The figure includes a clutch CL1 and a sensor S1.

The CPU 101 is a central processing unit of the main device 1, and the CPU 102
Is a central processing unit of the optional device 2. CPU101 and
The CPU 102 communicates with each other via the transistors Q1 and Q2.

The transistors Q3 and Q4 drive the clutch CL1 and the motor M1, respectively. The resistor R4 and the Zener diode ZD1 form a constant voltage circuit,
The power supply voltage of 102 is made.

Usually, a capacitor C1 for suppressing voltage fluctuation of the power source due to load fluctuation is connected to a power source (+24 V in this example) of such an optional device. As the capacitor C1, a capacitor having a large solution and a large capacity is connected if the predicted load fluctuation is large.

[Problems to be Solved by the Invention] By the way, when connecting the optional device 2 to the main device 1, it is generally pointed out that the power supply of the main device 1 is turned off according to an instruction manual or the like. In some cases, the connection is made without actually turning off the power.

Some devices must be connected without turning off the power.

In such a case where the connection is made without turning off the power, when the optional device 2 is brought close to the main device 1, a spark is generated in the power supply connector CN1. This phenomenon becomes more conspicuous as the capacitance of the capacitor C1 increases and as the supplied voltage increases.

This spark has the disadvantage that the connector CN1 is deteriorated and the user is anxious.

Further, when the optional device 2 is connected without turning off the power of the main device 1 as described above, there is a disadvantage that a reset circuit malfunctions due to chattering and the like.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a power supply control device that supplies power from another device having a power supply to a load via two power supply lines. A switch means for supplying power from the other device to the load, and two power lines on the other device side and two power lines on the power supply device side, Forming means for forming a circuit for passing a weak current including at least the power supply, the two power supply lines on the other device side, and the two power supply lines on the power supply device side in response to the coupling, Control means for turning on the switch means in response to the formation of the circuit by the formation means, and controlling supply of power from the other device to the load. It is an object of the present invention to provide a power supply control device.

Embodiment FIG. 1 is a circuit diagram showing a first embodiment of the present invention.
In the following description, the same components as those shown in FIG. 6 will be denoted by the same reference numerals.

In this embodiment, the optional device 2 connected to the main device 1 includes, for example, a motor M1, a clutch CL1, and a sensor S1.
Is provided.

The CPU 101 is a central processing unit of the main device 1, and the CPU 102 is a central processing unit of the optional device 2. These CPU101 and
The CPU 102 communicates with each other via the transistors Q1 and Q2.

Transistors Q3 and Q4 are clutch CL1 and motor M, respectively.
This element controls on / off of 1.

The resistor R4 and the Zener diode ZD1 are connected to the voltage V ₁ [v]
And is used for the power supply voltage of the CPU 102 and the like.

Capacitor C1, a load change, a smoothing capacitor supply voltage V ₀ is has been inserted in order to prevent the variation.

Relay RL1 is by its contacts rl1, a switching means for switching whether or not to send or sending power V ₀ to the option device 2.

The transistor Q5 is a transistor that drives the relay RL1.

The resistor R9 is a detecting means for detecting whether or not the optional device 2 and the ground line of the main device 1 are connected.

The resistors R0 and R15, the capacitor C0 and the diode D0
It constitutes a reset circuit.

The resistor R14 is a resistor for discharging the electric charge of the capacitor C1 when the optional device 2 is detached from the main device 1.

In the above configuration, when the optional device 2 is not connected to the main device 1, the port P11 of the CPU 101
“H” level is input. When the “H” level is input to the port P11, the CPU 101 determines that the optional device 2 and the main device 1 are not connected, keeps the port P12 at the “L” level, and sets the transistor Q5 And the relay RL1 is kept off.

When the optional device 2 is connected to the main device 1, an “L” level is input to the port P 11 of the CPU 101. At this time, the CPU 101 operates the optional device 2 and the main device 1
There is judged to have been connected, after a predetermined time, the port P12 of the CPU101 and the "H" level to turn on the transistors Q5 and RL1, supplies power V ₀ to the option device 2.

As described above, after detecting that the optional device 2 is connected to the main device 1, in order to supply power to the optional device 2, the optional device 2 is connected with the main device 1 turned on. However, no spark occurs at the connector CN1. Further, the reset circuit does not malfunction due to chattering at the time of connection.

 FIG. 2 is a circuit diagram showing a second embodiment of the present invention.

In the second embodiment, the relay RL1 as the switch means described in the first embodiment is arranged on the option device 2 side, and the same effect as in the first embodiment can be obtained.

In addition, comparing the second embodiment with the first embodiment, when the switch means is arranged on the option device 2 side, the number of connectors is increased by one, but the switch means is more expensive than one connector. Has an effect that the cost of the main device can be reduced.

Further, in the first embodiment, if the connectors CN4 and CN5 are connected, the port P11 of the CPU 101 becomes "L" level, so that the switch means is turned on after a predetermined time even if the connector CN1 is not connected. There was a problem.
However, in the case of the second embodiment, when the connector CN1 is not connected, the relay RL1 serving as the switch means is not provided.
No current is supplied to operate the
Only when CN5 and CN6 are connected, the switching means does not turn on, and it is possible to obtain the certainty of the operation that the switching means is turned on only when the connectors CN5, CN6, CN2 and CN1 are connected.

 FIG. 3 is a circuit diagram showing a third embodiment of the present invention.

In the second embodiment, the connection between the optional device 2 and the main device is detected by detecting the connection of the ground line. However, in the third embodiment, the voltage of the power supply line before the contact rl1 of the optional device 2 is detected. By detecting, the connection between the optional device 2 and the main device is detected.

The resistors R9, R10 is a partial pressure resistance of the power supply voltage V _0, Zener diode ZD0 is intended to prevent the input overvoltage to CPU 101. Hereinafter, the operation will be described by folding.

In the third embodiment, when the optional device 2 is not connected to the main device 1, an "L" level is input to the port P11 of the CPU 101. When the “L” level is input to the port P11, the CPU 101
Is determined not to be connected, the port P12 is kept at "L", the transistor Q5 and the relay RL1 are kept off, and power is not supplied to the circuit after the contact rl1 of the optional device 2.

Further, when the optional device 2 is connected to the main device 1, the port P11 of the CPU 101 Is input.

Therefore, when the values of R9 and R10 are selected so that this voltage becomes the “H” level of the CPU 101, the “H” level is input to the port P11 of the CPU 101, and the CPU 101 Judges that the connection is established, sets port P12 to "H" level, turns on transistor Q5,
RL1 is turned on, and power is supplied to the circuit after the contact rl1 of the optional device 2.

In this manner, the same effect as in the second embodiment can be obtained in this configuration.

 FIG. 4 is a circuit diagram showing a fourth embodiment of the present invention.

This fourth embodiment is a modification of the configuration of the power supply detecting portion of the third embodiment, and the other configuration is the same as that of the third embodiment.

The first embodiment has a demerit that the switch means operates after a predetermined time even if the power supply is not connected if the ground line is connected. In addition, the second and third embodiments have Although there is a possibility that the switch means may be repeatedly turned on and off even when the connection of the device 1 is unstable, in the fourth embodiment, the resistor R9 in the third embodiment is not used.
If, divide the power source voltage V ₀ min by the parallel resistor R10, R11 which is grounded divided into main device 1 side and the option device 2 sides, by supplying to the port P11, to eliminate the disadvantages as described above be able to. The details will be described below.

In the fourth embodiment, when the optional device 2 is not connected, or when the power supply connector CN1 is not connected, an “L” level is input to the port P11 of the CPU 101. When the optional device 2 is connected and the power supply connector CN1 and the ground connector CN6 are connected, the port P11 of the CPU 101 Is input.

If the optional device 2 is connected but the ground line is not connected, the port P11 of the CPU 101 is Is input.

Since the voltages V2 and V3 have a relationship of V3>V2> “L” level, for example, if an analog input port is used as the port P11 of the CPU 101, the voltages V2 and V3 can be easily identified. .

Only when the voltage input to the port P11 of the CPU 101 is the above-described V2, the port P12 of the CPU 101 is set to the “H” level, the transistor Q5 is turned on, the relay RL1 is turned on, and electric power is supplied to the circuit after the contact rl1. Control to supply.

As a result, only when it is detected that not only the power supply line but also both the ground line and the power supply line are connected, power is supplied to the circuits after the contact rl1.

By controlling the port P12 of the CPU 101 to the "H" level only when the voltage V2 is input to the port P11 of the CPU 101 for a predetermined time or more, the first
Power can be supplied more stably than in the third to third embodiments.

 FIG. 5 is a circuit diagram showing a fifth embodiment of the present invention.

In this embodiment, a transistor Q6 is used as a switch.

Also in this embodiment, similarly to the above-described second to fourth embodiments, the base current does not flow through the transistor Q6 if only one of the ground line and the power supply line of the optional device 2 and the main device 1 is connected. Therefore, the transistor Q6 remains off, and the transistor Q6 of the optional device 2
No power is supplied to the subsequent circuits.

When both the ground line and the power supply line are connected, the power supply voltage V ₀ (main device side) → connector CN1 → emitter of transistor Q6 (optional device side) → the same base → resistance R12 → resistance R13 → Connector CN4 → GND (Main device side)
The base current flows through the transistor Q6 in the route of (2), the transistor Q6 turns on, and the transistor Q6 of the optional device 2
Thereafter, power is supplied.

The capacitor C2 is for preventing malfunction due to chattering when the optional device 2 is attached.

In the case of the configuration as in the fifth embodiment, in addition to the merits of the first to fourth embodiments, the optional device 2
There is an advantage that a port of the CPU 101 for detection of the switch and control of the switch means is not required, which is particularly effective when the number of ports of the CPU 101 is small. Alternatively, since the number of ports of the CPU 101 is reduced, an effect that a cheaper CPU can be selected also occurs.

Further, in the fifth embodiment, there is an advantage that the number of connectors between the optional device 2 and the main device 1 can be reduced.

[Effect of the Invention] As described above, according to the first aspect of the present invention,
In a power supply control device that supplies power from another device having a power supply to a load via two power supply lines, two power supply lines on the other device side and two power supply lines on the power supply control device side are respectively provided. Forming a circuit for passing a weak current including at least the power supply and the two power lines on the other device side and the two power lines on the power supply control device side in response to the coupling, and forming the circuit; In response, the switch means is turned on, and control is performed so as to supply power from another device to the load, so that both the two power lines of the other device and the power supply control device are securely connected. Can be supplied to the load after the direct detection, and a spark when connecting the power supply control device to another device can be prevented. So, for example,
This has the effect of preventing damage to the connection terminal due to sparks and eliminating user anxiety.

[Brief description of the drawings]

 FIG. 1 is a circuit diagram showing a first embodiment of the present invention. FIG. 2 is a circuit diagram showing a second embodiment of the present invention. FIG. 3 is a circuit diagram showing a third embodiment of the present invention. FIG. 4 is a circuit diagram showing a fourth embodiment of the present invention. FIG. 5 is a circuit diagram showing a fourth embodiment of the present invention. FIG. 6 is a circuit diagram showing an example of the prior art. 1 ... Main device, 2 ... Option device, 101, 102 ... CPU, CL1 ... Clutch, C0-C1 ... Capacitor, CN1-CN6 ... Connector, D0, D1 ... Diode, M1 ... Motor, Q1 to Q6: Transistor, R0 to R15: Resistor, RL1: Relay, rl1: Contact, S1: Sensor, ZD0, ZD1: Zener diode.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kaoru Sato 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Makoto Abe 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon (72) Inventor Kazuhiko Okazawa 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Toshihiko Inuyama 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. ( 72) Inventor Masanori Ishizu 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (56) References JP-A-2-12512 (JP, A) JP-A-58-168125 (JP, A) ( 58) Fields surveyed (Int.Cl. ⁶ , DB name) H02J 1/00 G06F 1/26 H04B 1/16

Claims (3)

(57) [Claims] 1. A power supply control device for supplying power from another device having a power supply to a load via two power supply lines, wherein the power supply control device is interposed at a stage preceding the load, wherein Switch means for supplying power to a load; at least the power source and the power source according to the coupling of the two power lines on the other device side and the two power lines on the power supply control device side, respectively. Forming means for forming a circuit for passing a weak current including two power supply lines on another device side and two power supply lines on the power supply control device side; according to the formation of the circuit by the forming means Control means for turning on the switch means and controlling to supply power from the other device to the load. 2. The power supply control device according to claim 1, wherein the two power supply lines are a power supply line and a ground line. 3. The power supply control device according to claim 1, further comprising a signal line for controlling a motor from the another device.